Add the ability to compile exports on traced modules (#24298)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/24298
This helps in situations like when you have `__{g,s}etstate__` on an `nn.Module` and you'd like to trace the module, but still preserve the serialization methods to make the module semantically correct
Test Plan: Imported from OSS
Differential Revision: D16799800
Pulled By: jamesr66a
fbshipit-source-id: 91c2957c94c9ec97a486ea376b2a3e3a821270af
